Visible Air Pollution
May 15, 2010 by Post Team
Visible Air Pollution:The atmosphere is almost entirely made up of invisible gaseous substances. Most major air pollutants are also invisible, although large amounts of them concentrated in areas such as cities can be seen as “smog.” Often visible air pollutant is particulate matter, especially when the surfaces of buildings and other structures have been exposed to it for long periods of time or when present in large quantities. Particulate matter consists of small particles of solid matter and / or droplets liquid.Natural sources include volcanic ash, pollen and dust blown by the wind.
Coal and oil burned by power plants and industries and diesel fuel burned by many vehicles are the main sources of man-made
particulate pollutants, but not all important sources are large scale. The use of wood in fireplaces and wood stoves also produces significant amounts of particulate matter in localized areas, although the total amounts are much lower than that of vehicles, power plants and industries.
Smog hanging over cities is the most known and obvious air pollution. But there are different types of pollution, some visible, some invisible that contribute to global warming. In general, any substance that people introduce into the atmosphere that have harmful effects on living organisms and the environment as air pollution.
Carbon dioxide, a greenhouse gas, is the main pollutant is the warming Earth. Although living things emit carbon dioxide when they breathe, carbon dioxide is widely regarded as a pollutant when associated with cars, airplanes, power plants and other human activities that involve the burning of fossil fuels such as gasoline and natural gas. In the past 150 years, these activities have pumped enough carbon dioxide to the atmosphere to increase their levels higher than they have been for hundreds of thousands of years.
Other greenhouse gases include methane, which comes from sources such as reservoirs and the gas emitted by livestock and chlorofluorocarbons (CFCs), used in refrigerants and aerosol propellants until they were banned because of their deteriorating effect on the layer Earth’s ozone.
Other pollutants associated with climate change is the sulfur dioxide, a component of smog. The sulfur dioxide and closely related chemicals known primarily as a cause of acid rain. But they also reflect light when released into the atmosphere, which keeps sunlight out and causes the Earth to cool. Volcanic eruptions can shed large amounts of sulfur dioxide into the atmosphere, sometimes causing a cooling that lasts for years. In fact, volcanoes used to be the main source of atmospheric sulfur dioxide, people today are.
Smog alerts in major urban areas throughout the country are not uncommon these days, and exposure to particulate matter (PM) has long been known as a serious health threat, linked to respiratory problems, heart attacks, lung cancer and, more recently, life-threatening blood clots. With so many sources of combustion processes that produce these fine particles, may be a surprise that this type of pollution is three times more dangerous to human health as previously thought.
Scientists at the Air Resources Board said that up to 24,000 Californians die on average 10 years prematurely each year from exposure to PM over a long period of time. Children, the elderly and those with weakened immune systems are at greater risk of experiencing adverse effects from exposure in the afternoon, even in small increments. They also found that shipping goods across the State is responsible for approximately 3,700 fatalities a year emissions from the ports of LA and Long Beach account for about 120 deaths per year.
The report, called “Methodology for estimating premature deaths associated with long-term exposure to Fine Airborne Particulate Matter in California”, was based onanlysis of 60 studies worldwide, including studies by the World Health Organization (WHO), and was submitted in May 1922 the Air Resources Board of California. “Particulate pollution is a silent murderer,” said Mary Nichols, chairman of the Air Resources Board. “We have to work even harder to reduce these emissions that shorten life by further addressing pollution sources head.”
PM particles are especially dangerous because they are so small, 20 times smaller than the width of a human hair. These tiny particles are inhaled deep into the lungs and embedded in tissue or absorbed into the bloodstream. PM comes from many sources, including trucks, passenger cars, off-road equipment, electric power generation and industrial plants, wood burning fireplaces, as well as forest and agricultural burning.
Photochemical smog is also featured in the regions of the tropics and subtropics, where savanna grasses are periodically burned. unpleasant properties smog is the result of irradiation by sunlight of hydrocarbons mainly caused by unburned gasoline emitted by automobiles and other combustion sources. The products of photochemical reactions include organic particles, ozone, aldehydes, ketones, peroxyacetyl nitrate, organic acids and other oxidants. Ozone is a gas created by the oxide or dioxide of nitrogen oxide when exposed to sunlight. Ozone causes eye irritation, impaired lung function, and damage to trees and crops. Another form of industrial smog is called smog.
This pollution is created by burning coal and heavy oil containing sulfur impurities in power plants, industrial plants, etc … Smog is composed mainly of a mixture of sulfur dioxide and fog. suspended droplets of sulfuric acid is formed from sulfur dioxide, and a variety of solid particles in suspension. This contamination is common during the winter in cities like London, Chicago, Pittsburgh. When these cities burned large amounts of coal and heavy oil production uncontrolled, large-scale problems were witnessed.
In 1952 London, England, 4,000 people died as a result of this form of fog. Today, coal and heavy oil are burned only in large boilers and control good enough or tall chimneys, so that the industrial smog is a minor problem. However, some countries such as China, Poland, Czechoslovakia and other Eastern European countries, still burn large amounts of coal without using adequate controls.
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